The present disclosure relates to an imaging device, and more particularly to an imaging device and an imaging apparatus which detect a phase difference.
In recent years, there has been spread use of an imaging apparatus such as a digital still camera which generates a captured image by imaging a subject such as a figure, and records the captured image generated. In addition, as the imaging apparatus, in order to make a photographing operation of a user simple, there has been widespread use of an imaging apparatus which has an auto focus (AF) function of automatically performing focus adjustment at the time of imaging.
As the imaging apparatus, there has been proposed an imaging apparatus in which, for example, light passing through an imaging lens is divided through pupil division so as to form a pair of images, and a position of the imaging lens is determined by measuring a gap between the formed images (detecting a phase difference). For example, there has been proposed an imaging apparatus in which both of pixels (phase difference detection pixels) for phase difference detection (focal point detection) which performs pupil division by blocking half of subject light sensed by a light sensing element and pixels for generation of captured images (image generation pixels) are provided in a single imaging device. In a case where the imaging apparatus performs phase difference detection, a pair of images is formed based on a signal from the phase difference detection pixels, and a focus misalignment amount is calculated by measuring a gap between the formed images. Thereafter, the imaging apparatus calculates a movement amount of the imaging lens based on the calculated focus misalignment amount, and performs focusing by adjusting a position of the imaging lens based on the calculated movement amount (focus adjustment).
Here, in order to perform the phase difference detection and image generation with higher accuracy, there has been proposed an imaging apparatus in which a light collection position in the phase difference detection pixels and a light collection position in the image generation pixels are made to be different from each other (for example, refer to Japanese Unexamined Patent Application Publication No. 2009-109965). In the imaging apparatus, characteristics of micro lenses provided in the phase difference detection pixels and characteristics of micro lenses provided in the image generation pixels are made to be different from each other by changing a lens thickness, a lens diameter, or a lens material. Alternatively, in the imaging apparatus, a distance between the micro lens and the light sensing element in the phase difference detection pixels and a difference between the micro lens and the light sensing element in the image generation pixels are made to be different from each other.